The problem is when the amp turns on, the music will crackle/hiss for about 1/2 second before it sounds like normal, then it sounds great. Now Ive heard of turn on thump but never this. Have you heard of this before? What do you think it might be? Thanks for any help.

BTW, I confirmed this issue in the house by using a power supply and ipod.

I opened up the amp to inspect and found this:

So what purpose do these caps serve so close to the speaker output? Could this be causing the issue?

So what purpose do these caps serve so close to the speaker output? Could this be causing the issue?

Those are output RC networks that clean up any out of bandwidth noise issues usually ultrasonic in nature. Most every amp has these and the Mylar caps look to have melted or have been damaged somehow. These should be replaced, and they are cheap to come by.
I agree these are most likely not the source of your noise issue but they may be a symptom of your noise issue < a by-product caused by the noise issue >

Once you find the noise issue I would replace these just for good measure...

I would start looking for bad solder joints and bad switches first. After that I would be looking into the muting circuitry and other more advanced issues. Freeze spray can be helpful in detecting bad solder and contact cleaner for the switches and pots..

Last edited by 1moreamp; 18th January 2010 at 12:36 AM.
Reason: addendum